Adiabatic calorimeter.



S. W. FARB. ADMBATIC CALGRNIETER. APPLICATION FILED AUG-4, 1916. mem@ Nw2"?, 19N;

.Saw awww/fora @u 35# @Hom/mus 11N TE 111111 SAMUEL W. PARCEL, OFURBANA, ILLINOIS.

ADIABATIC CALORIMETER.

To aU whom t may concern.'

Be it known that l, SAMUEL lV. PARK, a citizen of the United States,residing at Urbana, in the county of Champaign and State of Illinois,have invented certain new and useful Improvements in AdiabaticCalorimeters; and lf do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

The present invention relates to calori1n eters and more particularly toa calorimeter in which an adiabatic condition may be maintained aboutthe combustion system during` the progress of the reaction therein.

ln usual calorimetric practice the combustion'is eifected in a closedcombustion chamber which is immersed in a body of liquid. As theincrease in temperature of this liquid is one of the factors to bemeasured in computing the heat of the reaction, it is necessary, inorder that greatest precision may be obtained, to prevent any transferof heat between the liquid and the surrounding medium during the timethe measurements are being taken.

ln the apparatus of the present invention this adiabatic condition forthe system is effectively maintained by apparatus of simpleconstruction.

In the preferred embodiment a jacket completely incloses the liquidwhich surrounds the combustion chamber', and means are provided forcirculating through this jacket a liquid, the temperature of which maybe easily raised or lowered or held at any exact point at will. Theapparatus, while permitting` a high degree of accuracy in measurements,is simple in construction and easy to manipulate. These features areimportant in calcrimeters intended for industrial use Other objects andadvantages of the present invention willbe made clear by the followingdetailed description which is to be taken in conjunction with theaccompanying drawings, wherein Figure 1 is a front elevation of theinstrument principally in section; and

Fig. 2 is a side elevation ofthe same, pring cipally in'section.

Referring to thedrawings, wherein simi- Speccaton of Letters Patent.Patmlgdl NQV 27, jpgjjljjo Application filed August 4, 1916.

Serial No. 1 13,087.

lar reference characters refer to similar parts throughout the viewsthereof, 10 represents a combustion chamber, or bomb, as it istechnically called. This bomb may be of any desired construction adaptedfor the purpose in hand and includes essentially a cup portion 11 and acover portion clamped together by means of an outer collar 12.

Upon the bottom of the cup of the bomb are formed lugs 15 which, whenthe bomb is in place in the oval can or receptacle 16, surround a boss17 formed in the base of the can. This can holds the liquid, the rise intemperature of which is used as one factor in computing the heat of thereaction occurring in the bomb. For obtaining this measurement, athermometer 18 is mounted upon the cover of the instrument in a mannerthat will hereinafter appear. rlrhe liquid within the can 16 should bestirred during the course of observations and hence a stirrer 19 mountedupon the cover of the apparatus provided.

Surrounding can 16 is a water-jacket having` al dead air chamber 2Owherein can 1G Vis mounted on insulating .supports 21. The water-jackethas inner and outer walls Q2 and 23 respectively and a top plate 24 towhich the inner wall 22 is attached at its upper edge. rheouter wall isattached to the top plate by a plurality of lugs 25 but between theselugs it terminates a short distance below the plate to form outlets 26through which water may overflow into a pocket or channel surroundingthe jacket and formed by a wall 27 attached to the outer surface of thewall 23. The pocket is provided with a drain pipe 28 wliicheX- tendsthrough the outer casing 29 of the apparatus. This outer casing Q9 ispreferably constructed of heat-insulating material and is somewhatlarger than the jacket so that there is an air paco between the wall 23of the latter and the inside of the casing.

The upper edge of the casing 2f) is formed with a recess 30 within whichthe top plate 24C is adapted to flt, thus insuring that the jacket andthe parts carried thereby are properly centered in the casing Since thejacket is attached to the plate Q4, all of the parts of the apparatusare suspended within the casing and can be readily removed, although inpractice the jacket will be kept in place since there are various otherparts of the instrument connected thereto and which must be removed inorder to take out the jacket.

The cover of thc apparatus comprises a chamber formed with side, top andbottom walls 35, 36 and 87 respectively. The top and side walls arecovered by an outer casing 38 of the same material as the casing 29 andhaving a recess at 39 corresponding to the recess 30 to tit over theouter edge of plate 24.

` Attached to the bottom 37 of the cover and passing through aperturesin the top plate 24 are a discharge tube 40 and a supply tube 41, thelatter having a sliding tit about a tube 42 leading from a centrifugalpump 43 mounted on the base of the jacket. The lower end of tube 41 hasan inverted V-shaped cut within which tits a corresponding wedge-shapedprojection on a collar 42 which is attached to tube 42. The tubes 41 and42 forni a pivotabout which the cover may be swung and the aboveconstruction constitutes a lifting device to automatically raise thecover as it is swung about the pivot tubes. While a slight lifting ofthe cover just at the start may be necessary it involves little or noinconvenience in operation but may be avoided by using a correspondinglifting arrangement comprising a wedgeshaped projection on the upperedge of casing 29 adapted to cooperate with an inverted V-shaped cut onthe lower edge of the cover to produce the initial lifting thereof.

The pump 43 is driven by a shaft 44 mounted in a sleeve 45 having awater-tight fit with the wall of the jacket. A bearing nut 46, a drivingpulley 47 and a bearing bracket 48 are provided. Upon the shaft areblades 49 to produce circulation of liquid through the jacket when theshaft is rotated. Although a centrifugal pump for raising the liquidfrom the bottom of the jacket to the chamber in the cover has beenillustrated, other devices for performing this function may be used.

The stirrer 19 for the vliquid within can 16 is mounted upon the coverin the manner shown in Fig. 2. A tube 55 forms an open passage throughthe chamber of the cover. The stirrer is mounted in a plug 56 set Withinthe passage and having a ledge adapted to rest upon the top of thccover. Pref erably the plug 56 should be made of heatinsulating materialin order to lessen the possibility of a transfer of heat by conductionthrough the shaft of the stirrer. To further attain this object theshaft of the stirrer may be made in two sections connected together by acoupling 56 of heatinsulating material such as hard rubber. To give thecoupling increased strength the hard rubber may be incased in brasstubing.

A pulley 57 is placed on the shaft for driving the same.

The thermometer 18 which extends within can 16 and a second thermometer60 extending into the jacket are arranged to passV of a set-screw 66.Rod 64 should extend` through top plate 24 and into chamber 2O aydistance at least equal to the distance the thermometers extend into theliquids in the can and jacket respectively. The reason for.` thisarrangement is to prevent the possi-A bility of breaking thethermometers when the cover is removed to obtain access to thecombustion bomb and can 16. vWhen the cover is swung about the tube 42as a pivot the automatic lifting device 42 raises the` coversutliciently to bring tube 40 out of the hole in plate 24 through whichit passes when the cover is 1n place, provided of course that thestirrer 19 be rst removed. by taking out plug 56 and the thermometers.

be raised so that rod 64 clears plate 24. The plug 56 is extended belowthe bottom 37 of the cover plate to avoid danger of bending the stem ofthe stirrer in case the user of the calorimeter forgets to remove theplug and stirrer before attempting to swing the cover plate. Under theseconditions the bottom of the plug would hit the inner wall 22 of thejacket to remind the user that the plug should be removed. In practicethe height to which it is necessary to raise the cover before it may beswung out of its normal position need be only about a quarter of an inchor less.-

Water or other liquid for the jacket is supplied through pipes and 71,one of which leads to a source of hot water supply and the other to coldwater. The iiow of water through these pipes is controlled by stop cocks72 and 73. Pipes 70 and 71 are connected by rubber tubings 74 and 7 5 topipes 7 6 and 77 leading through the casing 29 and connected to theouter wall 23 of the jacket at points opposite the end of shaft 44. Itis advisable to make these water supply tribes in sections connectedtogether by a rubber tubing in order to prevent the conduction of heatfrom the wall of the jacket through the Ymetal of the pipes. For thesame reason it is advisable to use a piece of rubber tubing 78 on theoveriiow pipe 28.

In a bomb of the character illustrated, means must be provided forstarting the chemical reaction within the bomb. In the present case itis done by an electric current,

1 ,2 497,993 gli the circuit for 'which may be traced from a terminalmounted on but insulated from the covel of the bomb. From this terminala conductor S1 leads over the edge of can 16, through a water-tightgland 82 inserted in the inner wall 22 of the jacket, through one of theoutlets 26 at the top of the jacket and through the casing 29 to abinding post 83. The other side of the circuit is formed through themetal of the bomb, it being understood that there is a spark gap,heating coil or other means for igniting the charge, suitably connectedbetween the terminal 80 and the metal of the bomb, when the cover of thebomb is in place. Since the bomb is resting upon the bottom ot can 16the circuit may be completed from the latter' to the inner wall 22 ofthe jacket by means of a spring-actuated contact device 81. To themetallic coverplate 2i .is attached by means of a binding post 85 aconductor 86 which passes through one of the outlets 26 and then throughthe casing 29 to a binding post 87. The binding posts may be connectedto any appropriate Source of current with switch for Controlling thecircuit thereof.

The method of using` the apparatus described above is as follows. Theparts of the bomb are clamped together after the proper materials havebeen placed therein and the bomb is set in place in can 16 which, forconvenience, may have been removed from the apparatus. A known quantityof water of a temperature slightly below that of the surrounding air isplaced in the can. There should be sufficient water to cover the bombcompletely. The can is then placed in chamber 20, the cover of theapparatus being swung aside to permit this operation. The cover is thenswung into place and lowered to rest upon top plate 24. The thermometersare then lowered into position and the stirrer 19 lowered into the waterand started to agitate the water. Water is then admitted to the jacketthrough pipes 70 and 71. Shaft 47 is start-ed to cause a steadycirculation through the jacket and some of the water is lifted by pumpt3 to lill the hollow cover to the level of outlet pipe 4:0. By propermanipulation of valves 72 and Z3 the temperature of. the water in thejacketing system may be made equal to that of the water in thecalorimetric system, the two thermometers being conveniently placed forsimultaneous readings. After equality of the two temperatures is insuredthe charge in the bomb is ignited and as the combustion proceeds thetemperature of the water in can 16 rises. By allowing more hot water toenter the jacket the temperature of the water therein may be Caused toincrease at substantially the same rate as does the temperature of thewater in can 16. There can thus be no external transfer of heat to orfrom the water in can 16, and the increase in temperature of this wateris due solely to the heat generated by the reaction taking place withinthe bomb.

Instead or' the procedure outlined above may in some cases be foundsulicient to bring the water in the jacket to an initial temperatureabout equal to that which the water in the can will attain, a roughcomputation serving to give the approximate increase of temperature thatwill occur when the reaction takes place.

After the observations have been completed the pump 113 is stopped, thethermometers are raised out of the liquids, thc stirrer 19 is removedand the cover is rotated and at the same time lifted by the cam actionof 42. Liquid in the chamber of the cover will drain out through pipes4l, 42 and pump 43, causing an overflow into the surrounding channel 27and out through the drain pipe 28. When the cover has been swung aside,can 16 and the bomb contained therein may be removed and the wire 81disconnected from the bomb.

It has been found in practice to be entirely possible to maintain thetemperature of the water in the jacket so near to the temperature of thewater surrounding the bomb that no gain or loss of heat in the interiorsystem can be detected. It may be stated in this connection that if thejacketing water is within 0.1 or 0.2 degrees ot the water in can 16 itwill be impossible to detect any radiation losses over a reasonablyshort period of time, say ten or fifteen minutes.

It will be understood that many changes may be made in the constructionoit an apparatus embodying the invention, without departing from theprinciple thereof.

I claim:

1. A calorimeter comprising in combination means adapted to hold acombustion bomb and submerging liquid, means completely enveloping saidlirst named means and adapted to contain a liquid, and means forcontrolling the temperature of the liquid in said surrounding means,substantially as described.

2. A calorimeter comprising in combination means adapted to hold acombustion bomb and submerging liquid, means constituting a chambercompletely enveloping said iirst named means and adapted to contain aliquid, and means for controlling the temperature of the liquid in saidenveloping chamber, substantially as described.

3. A calorimeter comprising in combination means adapted to hold acombustion bomb and submerging liquid, means constituting a chambercompletely enveloping said irst named means and adapted to contain aliquid, and means for maintaining a circulation of liquid throughoutsaid enveloping chamber, substantially as described.

4l. A calorimeter comprising in combination means adapted to hold acombustion bomb and submerging liquid, means constituting a chambercompletely enveloping said first named means and adapted to contain aliquid, means for maintaining a circulation of liquid throughout saidenveloping chamber, and means for controlling the temperature of theliquid in said enveloping chamber, substantially as described.

5. A calorimeter comprising in combination means adapted to hold acombustion bomb and submerging liquid, means constituting a chambercompletely enveloping said first named means and adapted to contain aliquid, means for maintaining a circulation of liquid throughout saidenveloping chamber, means for controlling the temperature of the liquidin said enveloping chamber, and means for measuring the .temperature ofboth of the liquids, substantially as described.

6. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle, a hollow member above said receptacle and havingcommunication with said jacket, and means for admitting liquid atdiiierent temperatures into said jacket and member at will,substantially as described.

7. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle, a hollow member above said receptacle and havingcommunication with said jacket, means for admitting liquid at differenttemperatures into said jacket and member at will, and means formaintaining a` circulation of liquid throughout said jacket and member,substantially as described.

8. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle and composed of inner and outer walls and a top plate, ahollow cover having communication with said jacket, and means foradmitting liquid of diiierent temperatures into said jacket and cover atwill, substantially as described.

9. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle and composed of inner and outer walls and a top plate, ahollow cover having communication with said jacket, means for admit-tingliquid of different temperatures into said jacket and cover at will, andmeans for maintaining a circulation of liquid throughout said jacket andcover, substantially as described.

Lampes 10. A calorimeter comprising in combination a receptacle adaptedto hold a combustion bomb and a submerging liquid, a jacket around saidreceptacle and composed of inner and outer walls and a top plate, ahollow detachable cover having communication with said jacket, and meansfor admitting liquid of different temperatures into said jacket andcover at will, substantially as described.

11. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and submerging liquid, a jacket around saidreceptacle, means for admitting liquid at different temperatures intosaid jacket at will, means for maintaining a circulation of liquidthroughout said jacket, and means for measuring the temperatures oi theliquids in said receptacle and said jacket, substantially as described.

12. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and submerging liquid, a jacket around said receptacleand composed of inner and outer walls and a top plate, a hollow coverhaving communication with said jacket, means for admitting liquid atdiiferent temperatures into said jacket at will, and a plurality ofthermometers mounted on said cover and normally extending through thesame into said receptacle and'said jacket, substantially as described.

13. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb Yand submerging liquid, a jacket around saidreceptacle, a cover having a chamber communicating with said jacket, aplurality of thermometers mounted on said cover and normally extendingthrough the same into said receptacle and jacket, and means formaintaining a circulation of liquid throughout said Vjacket and coverand over the bulb of the thermometer eX- tending within said jacket,substantially as described.

14. A calorimeter comprising inl combina-- tion a receptacle adapted tohold a combustion bomb and submerging liquid, a jacket around saidreceptacle, a coverrhaving a chamber communicating with said jacket,means for maintaining a circulation of liquid throughout said jacket andcover, and means for maintaining lthe temperatures of the submergingliquid and the jacket liquid substantially the same, substantially asdescribed.

15. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle, a hollow cover above said receptacle and jacket, meansbetween said cover and said jacket serving as a communicating passagebetween the two and also as a pivot about which the cover rio may berotated to remove the same from its normal position, substantially asdescribed.

16. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle, a hollow cover above so formed as to maintain apredetermined.

depth of liquid in said cover, substantially as described.

l?. A calorimeter comprising, in combination, a receptacle adapted tohold a combustion bomb and submerging liquid, a jacket surrounding saidreceptacle, a hollow member above said receptacle and havingcommunication with said jacket, thermometers adapted to extend throughsaid hollow member and within said receptacle and jacket, and anadjustable support for said thermometers mounted on said hollow member;substantially as described.

18., A calorimeter comprising in combination a receptacle adapted tohold a combustion bomb and submerging liquid, a jacket around saidreceptacle, a cover having a chamber communicating with said jacket,thermometers mounted upon said cover and adapted to extend within saidreceptacle and jacket, and an adjustable support for sai/l thermometersincluding means for preventingl rotation of said covers when saidthermometers extend below said cover, substantiallj7 as described.

19. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and submerging liquid, a jacket around said receptacleand composed of inner and outer walls and a top plate, a cover having` achamber communicating with said jacket, thermometers mounted upon saidcover and adapted to extend within said receptacle and said jacket, andan adjustable support for said thermometers comprising a rod extendingthrough said cover and said top plate when said thermometers extendbelow said cover to prevent rotation of said cover at such times, andmeans for maintaining said rod in any desired position of adjustment,substantially as described.

20. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a jacket around saidreceptacle composed of inner and outer walls and a top plate to whichsaid walls are attached, a cover formed with a chamber therein, a tubecommunicating with said chamber and extending downwardly through saidplate into said jacket,

a second tube slidably connected to said first named tube and attachedto the wall oi said jacket, means within said second tube for raisingliquid upwardly therethrough and means for controlling the temperatureot the liquid in said jacket, substantially as described. i

2l. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a j acket around saidreceptacle composed of inner and outer walls and a top plate to whichsaid walls are attached, a cover formed with a chamber therein, a tubecommunicating with said chamber and extending downwardly through saidplate into said jacket, a second tube slidably connected to said firstnamed tube and attached to the wall of said jacket, means within saidsecond tube for raising liquid up iardly therethrough, means forcontrolling the temperature of the liquid in said jacket, and anoverflow tube communicating with said chamber and extendingl downwardlythrough said top plate between the walls of said jacket, substantiallyas described.

A calorimeter comprising` in combination a receptacle adapted to hold acombustion bomb and submerging liquid, a jacket around said receptaclecomposed of inner and outer walls and a top plate to which said wallsare attached, a cover formed with a chamber therein, a tubecommunicating with said chamber and extending downwardly through saidplate into said acket, a tube telescopically associated with said firstnamed tube and attached to a wall of said jacket, means within saidsecond tube for raising liquid upwardly therethrough, and means formaintaining a circulation of liquid toward said raising means,substantially as described.

A. calorimeter comprising in combination a receptacle adapted to hold acombustion bomb and a submerging liquid, a acket around said receptacleand composed of inner and outer walls and a top plate to which saidwalls are attached, the outer wall being formed with an outlet adjacentsaid top plate, a pocket upon the outside of the said jacket, a coverformed with a chamber therein, passageways between said chamber and saidjacket, means for admitting liquid at different temperatures to saidjacket, and means for draining liquid from said pocket, substantially asdescribed.

24. The method of protecting a calorimeter system from transfer of heatexternally, which consists in surrounding the system with a circulatingliquid and maintaining said liquid at a temperature approximating theexternal temperature or' said system.

25. A calorimeter comprising in combination a receptacle adapted to holda combustion bomb and a submerging liquid, a acket around saidreceptacle, a hollow cover above said receptacle and jacket, meansbetween said cover and said jacket serving as a communicating passagebetween the two and also as a pivot about which the cover may Copies ofthis patent may be obtained for five cents each, by addressing the be'rotated to remove the same from vits normal position, and meansassociated with said first-named means for automatically lifting thecover as it '1s rotated; substantially as described.

In testimony whereof I aiX my sgnature.

SAMUEL W. PARE.

Commissioner of Patents.

Washington, D. C.

